Observations on the Behavior, Genetics, and Cytology of Two South African Digitaria valida Stent Accessions in Puerto Rico

Abstract

A remarkable improvement of inflorescence was induced in a sample of 11 Digitaria valida Stent accessions by prolongation of the daylight to approximately 16 hours. Two accessions, labeled 1950C and 1953A, showed the best reproductive performance under these conditions. Both developed some viable seed, and despite their poor germination, a progeny was obtained from both. Types aberrant from the mother type grew in both progenies. Obviously, a genetic recombination had taken place, although it remains uncertain, whether it was by crossing or by automixis. A cytological study revealed a high pollen stainability and an almost regular PMC meiosis in the parent plants. 1950C has extra chromosomes, apparently accessories with little genetic effects. An analysis of the embryosac development revealed a normal sac in about 50 percent of the cases and a suppression of the apomictic sac in others. It is concluded that the accessions 1950C and 1953A can be used in crossing experiments.